Stent crimping system and method

ABSTRACT

A stent crimping assembly is provided for crimping a stent from a first diameter to a reduced second diameter. The crimping assembly includes a plurality of movable wedges disposed about a rotational axis to form a wedge assembly. Each wedge includes a respective first side and a second side converging to form a tip portion. The tip portions are arranged to collectively form an iris about the rotational axis thereof. The iris defines a crimp aperture about which the movable wedges are disposed. A control unit is electronically programmed to control the mechanical components. A method of calibrating the control unit includes inserting a quill of known diameter into the iris and reducing the diameter of the iris onto the quill.

CROSS-REFERENCES TO RELATED APPLICATIONS

This application is a division of U.S. Ser. No. 12/050,031, filed Mar.17, 2008, now U.S. Pat. No. 8,215,149 which is a continuation of U.S.Ser. No. 11/191,159, filed Jul. 26, 2005, now U.S. Pat. No. 7,389,670,issued Jun. 24, 2008, which claims priority to U.S. ProvisionalApplication Ser. No. 60/591,260, filed, Jul. 26, 2004, all of which areincorporated by reference in their entirety. Applicant claims priorityto all of the applications in the chain.

FIELD OF THE INVENTION

The present invention relates generally to intraluminal devices, andmore particularly relates to apparatus and methods for reducing the sizeof these devices, such as a stent, stent-graft, graft or vena cavafilter, for percutaneous transluminal delivery thereof.

BACKGROUND

A number of vascular diagnostic and interventional medical proceduresare now performed translumenally. For example, catheter is introduced tothe vascular system at a convenient access location and guided throughthe vascular system to a target location using established techniques.Such procedures require vascular access, which is usually establishedduring the well-known Seldinger technique. Vascular access is generallyprovided through an introducer sheath, which is positioned to extendfrom outside the patient body, through a puncture in the femoral arteryfor example, and into the vascular lumen. Catheters or other medicaldevices are advanced into the patient's vasculature through theintroducer sheath, and procedures such as balloon angioplasty, stentplacement, etc. are performed.

In particular, stents and stmt delivery assemblies are utilized in anumber of medical procedures and situations, and as such their structureand function are well known. A stmt is a generally cylindricalprosthesis introduced via a catheter into a lumen of a body vessel in aconfiguration having a generally reduced diameter for transport anddelivery, and then expanded to a diameter of the target vessel whendeployed. In its expanded configuration, the stent supports andreinforces the vessel walls while maintaining the vessel in an open,unobstructed condition.

Balloon expandable stents are well known and widely available in avariety of designs and configurations. Balloon expandable stents arecrimped to their reduced diameter about the delivery catheter, thenmaneuvered to the deployment site and expanded to the vessel diameter byfluid inflation of a balloon positioned between the stent and thedelivery catheter. One example of a stent is described in US patentapplication having Publication No. 2004/0093073, published May 13, 2004,the content of which is incorporated herein by reference.

During advancement of the stem, through a body vessel to a deploymentsite, the crimped stent must capable of securely maintaining its axialposition on the delivery catheter. That is, the crimped stent must nottranslocate proximally or distally during advancement, and especiallymust not dislodge from the catheter. Stents that are not properlycrimped, secured or retained to the delivery catheter may slip and willeither be lost, be deployed in the wrong location or only be partiallydeployed. Moreover, the stent must be crimped in such a way as tominimize or prevent distortion of the stent, and thereby, minimize orprevent abrasion and/or trauma to the vessel walls. Additionally, if astent has been coated with a beneficial agent, care must be taken whencrimping the stent onto the delivery device that the coating is notdisturbed or removed from the stent during the crimping process.

In the past, crimping has been performed by hand, often resulting in anundesirable application of uneven radial crimping forces to the stent.Such a stent must either be discarded or re-crimped. Stents that havebeen crimped multiple times can suffer from fatigue and may be scored orotherwise marked which can cause thrombosis. In fact, a poorly crimpedstent can also damage the underlying balloon.

In addition to hand crimping of stents, automated crimping machines havebeen developed, wherein the automated crimping machines provide a moreconsistent crimp radial force during the crimping process or consistentprofile. In addition to providing consistent crimping forces, many othercrimping parameters can be closely controlled through the use ofcomputer controls or mechanical controls. An example of such anautomated crimping machine and related crimping methods can be seen inU.S. Pat. No. 6,629,350 to Motsenbocker. The crimping machine shown anddescribed in the '350 patent includes a crimp head comprising aplurality of segments, wherein one end of each of the segments isconstrained to rotate about a pin wherein the other end of the segmentsis allowed to translate about a second pin. In this arrangement, thetranslation of the second end of each of the segments controls the sizeof the opening formed by the distal ends of the segments. A shortcomingof such a design is wear of each of the segments at the pins. Theincreased wear increases the tolerances through which the crimp head canbe operated, eventually the crimp head can no longer be held to adesired tolerance and therefore must be rebuilt. Thus there is a needfor an improved crimp head design that can be held to tighter tolerancesfor a significant period of operation.

In addition to the balloon expandable stents described above, it wouldbe desirable to provide a stent crimping system capable of loading(i.e., crimping) selfexpanding stents into a delivery device, whereinthe stent can be chilled during compression. Further still, oncecompressed into a delivery diameter, the crimped stent must then beinserted into a distal end of a delivery system while maintaining thedelivery profile. In order to accomplish this, the crimping head must beconstructed such that minimal friction exists between the stent and thehead. Additionally, the delivery device must be retained relative to thecrimping head and then advanced a known distance to insert the crimpedstent, without damaging the delivery device.

SUMMARY OF THE INVENTION

The present invention provides an apparatus and methods for mechanicallycrimping a generally tubular stent from a first diameter to a seconddiameter. A stent crimping assembly is provided that includes aplurality of movable wedges having respective first side and a secondside converging to form a tip portion. The tip portions are arranged tocollectively form an iris about a rotational axis thereof. The irisdefines a crimp aperture about which the movable wedges are disposed.Each wedge is associated with a stationary structure and a rotationalactuation unit such that during rotation of the actuation unit about therotational axis, the iris is caused to rotate about the rotational axis,relative the stationary structure, for inward movement of the wedges todecrease the size of the crimp aperture and outward movement of thewedges to increase the size of the crimp aperture.

Accordingly, during the crimping procedure, the stent is also caused torotate with the iris. When released, the partially or fully crimpedstent will remain at least partially rotated relative to the initialposition before a crimp. This is advantageous for any subsequentlyrepeat crimp. Often, in a conventional crimping process, the crimpshould be repeated several times in order to achieve a smaller profileand better and more uniform circularity. Each time, between operations,the stent or crimper should be rotated relative to each other to achievethis result. In the present invention, this rotational procedureautomatically becomes part of the process, and hence the manual processof rotating the stent or crimper during the repeat crimp procedure canbe eliminated.

In one specific embodiment, the movable wedges have at least one endsection coupled to the stationary structure for relative rotationaldisplacement therebetween, and another section of the movable wedgecoupled to the actuation unit for substantially relative lineardisplacement therebetween. The rotational coupling of each wedge to thestationary structure is positioned proximate to a distal portion of therespective wedge, and the linear coupling of each wedge to the actuationunit is positioned proximate to a proximal portion of the respectivewedge.

A further specific arrangement, the relative rotation displacement ofeach wedge is about a respective rotational axis that extendssubstantially parallel to the rotational axis of the iris. The relativelinear displacement of each wedge is in a direction that extendssubstantially perpendicular to a respective bisecting plane of eachwedge. The rotational coupling of each wedge to the stationary structurefurther includes a respective linear displacement along a respectivebisecting plane of each wedge for movement toward the aperture duringthe inward movement thereof, and movement away from the aperture duringthe outward movement thereof.

Another embodiment includes the stationary structure with a stationaryend wall that includes a plurality of bearing devices disposed about therotational axis of the iris. Each bearing device is associated with onerespective wedge, and each wedge end section defining the elongated slotextending in a direction along the respective centerline of the wedge.

In yet another specific embodiment, the actuation unit includes ahousing enclosing the plurality of movable wedges. The housing rotatablycouples the stationary end wall for rotational displacement about therotational axis of the iris. A respective slider mechanism couples arespective wedge to the housing for the respective substantially lineardisplacement of the respective proximal portion of the wedge to thehousing during the rotational displacement of the housing. The slidermechanism includes a linear bearing device mounted to the wedge, and acarriage unit slideably coupled to the bearing device for movement in adirection substantially perpendicular to respective bisector of thewedge.

In another aspect of the present invention, a stmt crimper systemincludes an iris composed of a plurality of movable wedges disposedabout an aperture. The iris includes a rotational axis about which thewedges rotate as a unit. The wedges are disposed between substantiallyconcentric first end walls and an actuation housing substantiallycentered about the rotational axis and rotatably coupled to the firstend walls. Each wedge is associated with the first end walls and theactuation housing such that during rotational movement of the actuationhousing, the iris is caused to rotate about the rotational axis,relative a stationary structure, for inward movement of the wedges todecrease the size of the aperture and outward movement of the wedges toincrease the size of the aperture.

In one specific embodiment, the first end walls are stationary end wallsaffixed relative to the stationary structure. In another arrangement,the actuation housing includes a pair of opposed rotational end wallsrotatably coupled to a respective first end wall. Each of the rotationalend walls and the first end walls are configured for rotationaldisplacement, relative one another, about the rotational axis.

In still another aspect of the present invention, a crimping apparatusis disclosed for reducing the diameter of a medical device. Theapparatus includes at least one end plate; at least one drive plate; anda crimping assembly. The crimping assembly includes a plurality ofblades, wherein the blades have a proximal and distal end and a taperedportion adjacent the distal end. A pivot member is disposed on each sideof each blade, and the pivot member is configured to be received by thedrive plate. The blades further include a sliding assembly, a portion ofthe sliding assembly coupled to the blade adjacent the proximal end anda second portion of the sliding assembly coupled to the end plate.

In yet another aspect of the present invention, a stmt crimping systemis provided including a chassis, a crimping assembly, a clampingassembly and a control unit. The clamp assembly that secures the medicaldevice includes a lower clamp device defining a seating groove formedand dimensioned to seat a portion of the medical device therein. Aretaining assembly includes an elastomeric member, the elastomericmember defining a contacting groove oriented in an opposed mannerproximate to at least a portion of the seating groove. An actuationmechanism is associated with the retaining assembly and the lower clampdevice such that operation thereof causes the retaining assembly to movebetween an opened condition, enabling positioning of the elongateddevice between the lower clamp device and the retaining assembly, and aclosed condition, retaining the medical device between the contactinggroove of the elastomeric member and the seating groove of the lowerclamp device.

In another specific embodiment, the clamp device includes a pivot leverrotatably mounted to the lower clamp device. The pivot lever cooperatesbetween the actuation mechanism and the retaining assembly for movementof the retaining assembly between the opened condition and the closedcondition.

The retaining assembly is coupled to the pivot lever proximal a distalportion of the lever member. Further, the actuation mechanism cooperateswith the pivot lever proximal a proximal portion thereof such that whenthe actuation mechanism is moved from a first position towards a secondposition, the pivot lever is caused to rotated about a rotational axisof the pivot pin which causes the retaining assembly to move from theopened condition toward the closed condition.

In yet another specific embodiment, the lower clamp device includes abase portion and a support plate extends distally from the base portion.The seating groove extends along an upper edge portion thereof from thebase portion to the support plate. The retaining assembly includes apair of plate members mounted to, and depending downwardly, from theelastomeric member on opposite sides of the support plate. Each platemember is coupled to the pivot lever at the distal portion thereof.

The pivot lever includes a pair of lever portions disposed on oppositesides of the lower clamp device support plate. E lever portion ispivotally mounted to a corresponding plate member through a securing pinextending therethrough. The support plate includes an elongated slotupon which the securing pin passes therethrough. The elongated slot beconfigured to accommodate the travel of the securing pin as theretaining assembly reciprocates between the opened condition and theclosed condition.

BRIEF DESCRIPTION OF THE DRAWINGS

The assembly of the present invention has other objects and features ofadvantage which will be more readily apparent from the followingdescription of the best mode of carrying out the invention and theappended claims, when taken in conjunction with the accompanyingdrawing, in which:

FIG. 1 is a top perspective view of a crimping assembly constructed inaccordance with the present invention, and illustrating a crimp aperturein an opened condition.

FIG. 2 is a top perspective view of the crimping assembly of FIG. 1 witha proximal rotational end wall and a proximal stationary end wallremoved.

FIG. 3 is an enlarged, fragmentary, top perspective view of the iris ofthe crimping assembly of FIG. 2.

FIG. 4 is a top perspective view of the crimping assembly of FIG. 2 withthe drum portion removed.

FIG. 5 is a top perspective view of the crimping assembly of FIG. 4,illustrating the crimp aperture in a closed condition.

FIG. 6 is an enlarged top perspective view of a single wedge device ofthe crimping assembly of FIG. 1.

FIG. 7 is a reduced top perspective view of the frame structure of thewedge device of the FIG. 6.

FIG. 8 is a diagram illustrating the trajectory of a single wedge duringoperation, in four positions.

FIG. 9 is a diagram illustrating the relative movement of four adjacentwedges during operation, in two positions.

FIG. 10 is a side elevation view, in cross-section, of the crimpingassembly of FIG. 1.

FIG. 11 is top perspective view of a drum portion of an actuation unitof the clamping assembly of FIG. 1.

FIG. 12 is a top plan view of an alternative embodiment crimping systemin accordance with the present invention.

FIG. 13 is an exploded top perspective of an alternative embodimentcrimp assembly of the crimping system of FIG. 12.

FIG. 14 is a top perspective view of a blade of the crimp assembly ofFIG. 13.

FIG. 15 is a front elevation view an end plate of the crimp assembly ofFIG. 13.

FIG. 16, is a rear elevation view of the end plate of FIG. 15.

FIG. 17A is a front elevation view a drive plate of the crimp assemblyof FIG. 13.

FIG. 17B is a side elevation view, in cross-section of the drive platetaken along the plane of the line 17B-17B in FIG. 17A.

FIG. 18 is an exploded top perspective view of a clamping assemblyconstructed in accordance with of the present invention.

FIG. 19 is a top perspective view of the clamping assembly of FIG. 18,illustrated in an opened condition.

FIG. 20 is a top perspective view of the clamping assembly of FIG. 20,illustrated in a closed condition.

FIG. 21 is a side elevation view of the clamping assembly of FIG. 19,illustrated in the opened condition.

FIG. 22 is a side elevation view of the clamping assembly of FIG. 21,illustrated in the closed condition.

FIG. 23 is an exploded bottom perspective view of the clamping assemblyof FIG. 18.

FIG. 24 is a bottom perspective view of the clamping assembly of FIG.23, illustrated in the opened condition.

FIG. 25 is a bottom perspective view of the clamping assembly of FIG.23, illustrated in the closed condition.

FIG. 26 is a front elevation view of the clamping assembly of FIG. 19,illustrated in the opened condition.

FIG. 27 is a front elevation view of the clamping assembly of FIG. 26illustrated in the closed condition.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

While the present invention will be described with reference to a fewspecific embodiments, the description is illustrative of the inventionand is not to be construed as limiting the invention. Variousmodifications to the present invention can be made to the preferredembodiments by those skilled in the art without departing from the truespirit and scope of the invention as defined by the appended claims. Itwill be noted here that for a better understanding, like components aredesignated by like reference numerals throughout the various figures.

Referring now to FIGS. 1-6, a stent crimping assembly, generallydesignated 20, is illustrated that defines a crimp aperture 21 forcrimping a stent (not shown) from a first diameter (FIG. 4) to a reducedsecond diameter (FIG. 5). This crimping assembly 20 includes a pluralityof movable blades or wedges 22 arranged in an assembly 25 around thecrimp aperture 21. Each wedge, as best viewed in FIGS. 3 and 6, includea first side 26 and a second side 27 that converge to form a distal tipportion 28. When assembled in the wedge assembly 25, the first andsecond sides 26, 27 of each wedge 22 are arranged substantially adjacentthe second and first sides 27, 26, respectively, of an adjacent wedge 22such that the tip portions 28 collectively form an iris 30. The iris 30defines the crimp aperture 21 centered about the iris rotational axis31. Hence, the distal portions of the wedges 22 are directed generallyinwardly while the proximal portions of the wedges are directedgenerally outwardly.

As will be described in greater detail below, the crimping assembly 20includes a stationary structure 32 and a rotational actuation unit 33that is rotatably associated with the stationary structure for rotationof the unit about the iris rotational axis 31. Each movable wedge 22 ofthe wedge assembly 25 is rotationally coupled to the stationarystructure 32 proximate to a respective distal portion thereof such thateach wedge 22 can rotate about a respective wedge rotational axis 34thereof. Collectively, the wedge rotational axes 34 are radially spacedabout the iris rotational axis 31 (FIG. 3). Each wedge rotational axisis oriented substantially parallel to, and circumferentiallyspaced-apart about, the iris rotational axis 31. Further, a proximalportion of each wedge 22 is coupled to the actuation unit 33 throughrespective linear slider mechanisms 36 for substantially lineardisplacement relative to its coupling to the actuation unit. Moreparticularly, as will be described the linear displacement is in adirection substantially perpendicular to a respective centerline orplane 37 bisecting the wedge 22.

In accordance with the present invention, since the linear slidermechanisms 36 are collectively caused to rotate with the actuation unit33 about the iris rotational axis 31, each wedge 22 is caused to rotateabout its wedge rotational axis 34, while simultaneously slidinglinearly (via the respective slider mechanism) relative to the rotatingactuation unit 33. Hence, the motion of the each wedge 22 relative afirst end wall 35′, 35″ and the stationary structure 32 (as well as tothe wedge rotational axis 34 which is fixed relative to the stationarystructure) is represented in the single wedge trajectory diagram of FIG.8 and the relative movement of the multiple wedges of FIG. 9.Collectively, the iris 30 itself is caused to rotate as a unit about theiris rotational axis 31, relative to the stationary structure 32. Thisis advantageous in that the stent is also caused to rotate. Whenreleased, the partially or fully crimped stent will remain at leastpartially rotated relative to the initial position before a crimp.Often, in a conventional crimping process, the crimp should be repeatedseveral times in order to achieve a smaller profile and better and moreuniform circularity. Each time, the stent or crimper should be rotatedbetween these operations relative to each other to achieve this result.In the present invention, this rotational procedure automaticallybecomes part of the process, and hence the manual process of rotatingthe stmt or crimper during the repeat crimp procedure can be eliminated.

Accordingly, in operation, when the actuation unit 33 is rotated aboutthe iris rotation axis, in a counter-clockwise direction shown in FIGS.1, 4 to the position of FIG. 5 (which illustrates the crimping assembly20 with most of the actuation unit removed), the counter-clockwisemotion is translated into both rotational movement of each respectivewedge about its wedge rotational axis 34, while further simultaneouslydisplacing each wedge linearly inward along the respective slidermechanism. The linear displacement, for each slider mechanism 36, is ina direction substantially perpendicular to a respective plane bisectingthe each wedge 22. As the entire iris 30 rotates relative to thestationary structure 32, the inward sliding movement of the wedges 22causes the aperture 21 to decrease in size. As the crimp aperture 21closes (FIG. 5), a radially inward force, as well as a counter clockwiserotational force, is applied by the blades to the medical device (e.g.,a stent) disposed in the aperture.

The actuation unit is rotated until the desired size reduction of theaperture and medical device is achieved. Subsequently, the actuationunit 33 is rotated in the oppose direction to permit removal of thedevice from the crimp aperture.

Turning now to FIGS. 6 and 7, a blade or wedge 22 of the crimpingassembly is shown and illustrated as having a wedge shape that isgenerally symmetrical about the respective centerline or bisecting plane37 thereof. In this specific embodiment, the wedge 22 includes anelongated hollow frame structure having an inwardly tapered distal endand a widened proximal portion with a substantially planar proximal end38. Preferably, the aforementioned first side 26 and the opposed secondside 27 are substantially planar, and taper inwardly to form a straighttip portion (thus forming a substantially polygonal crimp aperture 21).The distal end of the first side 26, however, may be slightly curvedtoward crimp aperture (not shown), so as to form a more circular-shapedaperture when the crimp aperture is fully closed or reduced in size.Further, the tip portion may also terminate at a sharp edge. Preferably,however, the edge is slightly rounded or beveled, eliminating a sharptip. This configuration facilitates sliding contact with the adjacentblade surfaces. Briefly, while the present invention has been shown anddescribed as providing sliding, abutting contact between the wedge sidewalls, it will be appreciated that there may be some clearancetherebetween with no sliding contact.

Depending upon the number of blades selected to form the iris 30, theconverging angle between the first side 26 and the second side 27 (i.e.,the tip angle a) can be selected accordingly. For example, the wedgeassembly may include as little as three wedges, and as many as sixteen.The maximum number of wedges is limited by the number thereof that canbe physically coupled together under the relevant size constraints. Asthe number of blades is increased, the profile of the aperture and ofthus of the crimped medical device becomes smoother. In the embodimentillustrated in FIGS. 1-5, twelve wedges 22 are employed where the firstside 26 and the second side 27 of each blade are in substantiallyadjacent one another, or in sliding contact with the second side 27 andthe first side 26, respectively, of the adjacent blades. Generally thetip angle a is less than or equal to 360/n where n is equal to thenumber of blades. For the twelve-blade embodiment illustrated, the tipangle a is in the range of about 30 Degrees or less.

As best illustrated in FIG. 6, each wedge 22 is further defined by asubstantially planar first end section 40′ and an opposed substantiallyplanar second end section 40″. Each face of the end section defines anelongated bearing slot (41′, 41″) extending substantially in a directionalong the centerline 37 that bisects each wedge. Each bearing slot ofthe set (41′, 41″) is further aligned relative to one another, and ispositioned proximate to the distal portion of the wedge 22.

The wedges 22 may be constructed of a material or a combination ofmaterials such as nylon, delrin, steel, aluminum, titanium, TEFLON®,plastics, composite materials, and other suitable materials. This hollowframing of the wedge 22 also may be constructed of multiple pieces thatmay be assembled to form a unitary member, or alternatively each wedge22 may be constructed as a unitary member. In another specificembodiment, each wedge 22 may include a replaceable blade insert 42 ateach distal end thereof. At a distal portion of each wedge 22, the firstside 26 thereof defines a step or shoulder portion 39 formed to seat theelongated blade insert 42 therein (FIG. 7). In this arrangement, oneside of the blade insert 42 seats substantially flush with the firstside 26 of the wedge, while an opposed side of the blade insert seatssubstantially flush with the second side 27. Accordingly, the entirecontacting surface that is employed to crimp a stent may be provided bythese replaceable blade inserts 42. Such blade inserts 42, by way ofexample, may also be composed of nylon, delrin, TEFLON®, plastics,composite materials, and other suitable materials. Such materialselections depend in part upon the material properties, such as thethermo insulation, the thermo conductivity, whether the frictiontherebetween is low or high, etc.

In accordance with one embodiment of the present invention, the firstend walls 35′, 35″ are substantially stationary, and are part of andmounted to stationary structure 32. These stationary end walls (i.e., aproximal end wall 35′ and a distal end wall 35″) are disposed atopposite ends of the wedge assembly 25. Preferably, these stationary endwalls 35′, 35″ each include an exterior surface and an opposed interiorface 43 that is to be oriented to face inwardly toward the wedgeassembly when assembled. A receiving port 45 extends therethrough fromthe exterior to the interior face 43 to that provides access to thecrimp aperture 21. Each end wall 35′, 35″ includes a respective hubportion 46 that is oriented to face inwardly, toward the wedge assembly25, during operation and assembly of the crimping assembly 20. Thestationary end walls 35′, 35″ each further include a mounting flange 47that extends radially outward from the hub portion 46.

FIGS. 1 and 10 best illustrate that the stationary structure 32 furtherincludes a support base 48 and a pair vertical supports 50′, 50″upstanding therefrom. Each vertical support 50′, 50″ is substantiallyrigidly mounted to the respective end wall mounting flange 47 to securethe end walls 35′, 35″ in a stationary manner. It will be appreciated,of course, that the stationary end walls may be rigidly supportedthrough any other conventional technique as well.

To rotatably support the assembly 25 of wedges 22 to the stationarystructure 32, each wedge 22 is rotatably coupled, at the opposed endsections 40′, 40″ thereof, to the corresponding stationary end wall 35′,35″ for rotation about a respective wedge rotational axis 34. As bestillustrated in FIGS. 2-5 and 10, such rotational support is provided bya plurality aligned bearing devices 51 disposed at the opposed endsections 40′, 40″ of each wedge 22. Each respective pair of bearingdevices 51 cooperate to define the respective wedge rotational axis 34about which each wedges individually rotates. To mount the wedgeassembly 25, the bearing device pairs are affixed to the interior face43 of the hub portions 46 of the stationary end walls 35′, 35″ andconfigured rotatably cooperate with, and support, the respective wedges22.

Briefly, each bearing device 51 includes a pivot shaft 52 having a pinend 53 suitable for affixed mounting into the interior face 43 of therespective hub portion 46 (FIGS. 4, 5 and 10). These pin ends 53 may befriction fit, threaded or adhered to the interior face 43 in any securemanner. The pivot shaft 52 on the interior face 43 of the proximalstationary end wall 35′ is to be co-axially aligned with the pivot shaft52 on the interior face 43 of the distal stationary end wall 35″ so thatthe respective wedge rotational axis 34 is substantially parallel to theiris rotational axis 31.

Rotatably mounted to each pivot shaft 52 is a corresponding wheel 55(flange) rotatably supported about the shaft through ball bearings orthe like. These wheel flanges 55 and pivot shafts 52 of the bearingdevices are configured for receipt in the corresponding bearing slots41′, 41″ defined by the first and second end sections 40′, 40″ of therespective wedge.

As illustrated, each bearing device 51 is aligned with its correspondingbearing on an opposite end of the wedge assembly. Collectively, thesebearing pairs are equally spaced apart radially about the irisrotational axis, thus also positioning the wedge rotational axes 34equally spaced apart radially about the iris rotational axis. Moreover,these radially spaced wedge rotational axes 34 are orientedsubstantially parallel to the iris rotational axis 31, which center therotation of the iris 30 about the iris rotational axis 31. Accordingly,during operational movement, the respective wedge rotational axes 34 ofthe wedge assembly 25 remain stationary relative the stationary endwalls 35′, 35″, while each respective wedge 22 simultaneously rotatesabout its wedge rotational axis, and slides substantially linearly adirection substantially perpendicular to the respective centerline 37 ofthe respective wedge 22.

In order to permit such linear sliding displacement in theaforementioned direction, each wedge 22 themselves must also be capableof sliding linearly along the respective bearing devices in a directionalong the centerline plane. The bearing slots 41′, 41″, each of whichextend in a direction along the centerline plane, accommodate thismotion.

Therefore, these bearing couplings not only promote relative rotation ofthe wedges 22 about the respective wedge rotational axis 34, via thewheel flanges 55, but also promote linear displacement along therespective bearing slot 41′, 41″ generally toward and away from the irisrotational axis. The width of the bearing slot, therefore, issufficiently larger than the diameter of the corresponding wheel flange55 to permit such sliding linear displacement along the elongatedbearing slot as well as to promote rotation of the respective wedge 22about the respective wedge rotational axis 34. The tolerance between theslot width and the wheel (flange) diameter, however, must also besufficiently small to reduce and minimize instability and chatter duringoperation.

In contrast, the length of the elongated bearing slots 41′, 41″ must besufficient to permit the relative linear displacement of wheel flange 55along the slot. This linear displacement essentially translates intomovement of the rotating wedges 22 respectively toward and away from thecrimp aperture 21.

While the present invention has been illustrated and described as havingthe bearing slots defined by the end sections 40′, 40″ of the wedges 22,and the bearing devices 51 mounted directly to the hub portions 46 ofthe stationary end walls 35′, 35″, it will be appreciated such mountingcomponentry can be easily reversed. In such a configuration, therefore,the bearing devices 51 can be mounted to the wedge end sections 40′,40″, while the bearing slots will be defined by the interior wall of thehub portion 46. In this arrangement, however, respective the bearingslots 41′, 41″ will not be substantially linear, and will shaped tosubstantially mirror the path of the wedge and wedges shown in thediagrams of FIGS. 8 and 9.

Referring back to FIG. 1, a rotational actuation unit 33 is rotatablymounted to the stationary structure 32 to actuate the rotation of thewedge assembly 25 about the iris rotational axis 31, and to cause theincrease or decrease of the diameter of the iris 30. Briefly, asabove-mentioned, the actuation unit 33 is rotatably coupled to thestationary end walls 35′, 35″ for rotation the iris rotational axis 31,while simultaneously individually coupled to the proximal portions ofthe respective wedges 22 for substantially linear displacementtherebetween.

In one specific embodiment, the actuation unit 33 is provided by ahousing structure that at least partially encloses the cylindrical wedgeassembly 25 therein. FIGS. 1 and 10 best illustrate that the rotationalactuation unit 33 includes a pair of rotational end walls (i.e., aproximal rotational end wall 56′ and the distal rotational end wall 56″)that rotatably cooperate with the corresponding stationary end walls35′, 35″, respectively, for rotational support. These rotational endwalls 56′, 56″ are disposed on the opposed ends of the wedge assembly25, and are rotatably coupled to the hub portions 46 of the stationaryend walls 35′, 35″ through respective rotational bearings 57.

Hence, each plate-like rotational end wall 56′, 56″ defines a centralbearing aperture 58 that is centered about the iris rotational axis,when rotatably supported to the respective hub portion 46. This bearingaperture 58 is defined by an inward facing mounting surface 60 of therotational end walls 56′, 56″ that, when centered, opposes an outwardfacing mounting surface 61 of the respective stationary end wall 35′,35″. As shown in FIG. 10, the rotational bearing 57, such as for examplea conventional ball bearing assembly, is disposed between these mountingsurfaces 60, 61 to provide rotational support of the respectiverotational end walls 56′, 56″ about the corresponding stationary endwalls 35′, 35″. These bearing units 57, hence, provide the primaryrotational support of the actuation unit 33 about the iris rotationaxis.

It will be appreciated, however, that such a ball bearing unit can beeliminated and a more direct bearing-style contact could be employedbetween the inward facing mounting surface 60 of the rotational endwalls 56′, 56″ and the outward facing mounting surface 61 of therespective stationary end wall 35′, 35″.

Further, it will be contemplated that the first end walls 35′, 35″(i.e., the stationary end walls when affixed to the stationary structure32) may also rotatably coupled to the stationary structure for rotationabout the aperture rotational axis. In this instance, both therotational end walls 56′, 56″ may be mounted to rotational supportstructure to enable relative rotation therebetween, and relative to thestationary structure 32, wherein the cross-support structure 62 (FIG.11) would be supported by a rotatable member such as bearings (notshown). In this embodiment, the end walls 35′, 35″, 56′ and 56″ would beconfigured to move either independent of each other or in conjunctionwith each other, the cross-support structure 62 being rotationallycoupled to the stationary structure 32.

To rigidify the actuation units, so as to operate as a single unit, across-support structure 62 laterally extends from the proximalrotational end wall 56′ to the distal rotational end wall 56″.Generally, in one specific arrangement, this support structure 62 may beprovided by a plurality of cross-beams that extend laterally across thewedge assembly 25. FIG. 16 best illustrates such a configuration wherethe cross-beams 140 extend across the wedge assembly, and arespaced-apart circumferentially about the aperture.

In the preferred embodiment of this specific arrangement, however, thecross-support structure 62 is provided by a unitary cylindrical-shapeddrum portion 63 (FIG. 11). As shown in FIGS. 1 and 10, this unitary drumrigidly mounts the proximal rotational end wall 56′ to the distalrotational end wall 56″, together as a unit. This cylindrical-shapedhousing structure is sized and dimensioned to essentially fully enclosethe entire wedge assembly 25 therein without impeding movement of thewedges during rotational movement of the actuation unit 33.

A handle member 65 can be mounted to the actuation unit 33 forrotational actuation of the unit about the iris rotational axis 31. Asillustrated in FIG. 1, a single handle member 65 can be mounted to theproximal rotational end wall 56′ for manual rotation thereof. It will beappreciated, however, that such handle member can be mounted to eitheror both rotational end walls 56′, 56″, as well as to the drum portion63. Moreover, as will be described in greater detail below, conventionalautomated controls can be incorporated as well to automate the actuationmovement.

In accordance with the present invention, a proximal portion of eachwedge 22 is slideably coupled to the actuation unit 33, via the slidermechanisms 36, to promote substantially linear displacement of the wedgerelative to the actuation unit. Each slider mechanism 36 is preferablydisposed between the actuation unit 33 and the proximal portion of therespective wedge, in a manner permitting substantially linear slidingdisplacement in a relative direction, substantially perpendicular to therespective centerline or bisecting plane 37 of the respective wedge 22.As mentioned above, this simultaneous, respective linear wedgedisplacement occurs as the entire wedge assembly 25 is rotating aboutthe iris rotational axis 31 as a unit, and as the wedges further rotateabout their respective wedge rotational axis 34.

In one specific embodiment, the slider mechanisms 36 include a pair ofspaced-apart substantially linear bearings 66 mounted to the respectivewedge 22, and a pair of corresponding carriage units 67 coupled to theactuation unit 33. These carriage units 67 are configured to tracklinearly along the associated linear bearing 66. In particular, as bestviewed in FIG. 7, the two rails or linear bearing 66 are seated andaffixed in a pair of corresponding alignment grooves 69 recessed thesurface of the substantially planar proximal end 38 of each respectivewedge 22. These alignment grooves 69 orient the respective linearbearing 66 so that the corresponding carriage units 67, in slidingcontact therewith, will slide a substantially linear directionsubstantially perpendicular to the respective centerline of the wedge.

The carriage units 67 are generally U-shaped having a substantiallyplanar outer surface, and a receiving slot 68 on an opposed surface thatfaces inwardly toward the respective wedge 22. These receiving slots 68are formed and dimensioned of sliding receipt of the correspondinglinear bearing 66 therein for linear displacement of the carriage emit67 therealong.

While the application of the pair of spaced-apart linear bearings 66 ispreferred for stability and alignment, it will be appreciated that asingle linear bearing or more than two bearing can be employed withoutdeparting from the true nature and scope of the present invention.

The crimping assembly 20 further includes a plurality of saddle unitsthat fixedly mount each pair of carriage units 67 to the actuation unit33. Each saddle unit 70 is configured to seat in a corresponding accessport 71 extending through the drum portion 63. These access ports 71 areequally spaced circumferentially about the drum portion 63, and providemounting access to the corresponding carriage units 67.

Each saddle unit 70 includes a base portion 72 and a pair of opposedmounting flanges 73 that seat against and mount to a correspondingshoulder portion 75 in each access port 71 (FIG. 10), via fasteners. Inturn, a substantially planar interior facing surface of each saddle unit70 abuts against and is aligned with the substantially planar outerfacing surface of the respective pair of carriage units 67. Using accesscavities 76, the respective saddle unit 70 can be secured to therespective pair of carriage units 67, which in turn rigidly secure thecarriage units to the actuation unit 33.

Accordingly, referring back to FIGS. 4 and 5, as the actuation unit 33is rotated as a unit in a counterclockwise direction about the irisrotational axis 31, the wedge assembly 25 is also caused to rotate as aunit about the iris rotational axis 31 in the counterclockwisedirection. Due to the intercoupling between the rotating actuation unit33 and the stationary structure 32, the rotational motion is partiallytranslated to linear motion of the slider mechanisms 36 as therespective carriage units 67 are caused to slide along their respectivelinear bearings 66. Consequently, the respective wedges 22 are thencaused to rotate about their respective wedge rotational axis 34 at therespective pair of bearing devices 51. Simultaneously, the wedges arecaused slide inwardly toward the crimp aperture 21 as the respectivewheel flanges 55 of the bearing devices 51 navigate along thecorresponding bearing slots 41 from an interior end to an exterior endthereof. Hence, the diameter of the crimp aperture 21 decreases in sizefrom the opened aperture condition of FIGS. 1-4 to the closed aperturecondition of FIG. 5. To move the wedges 22 outward to increase the sizeof the crimp aperture, the motion is simply reversed and will not bedescribed in detail. Once the wedges reach the smallest crimp diameter,continuing past this point will cause the wedges to move back to theopened aperture condition. Minor adjustments, hence, would allowoperation of this device in either direction (i.e., clockwise orcounter-clockwise.

In another embodiment of the present invention, it is furthercontemplated that the crimping system may additionally include a chillerunit (not shown) wherein the chiller unit is configured to chill or coolthe chamber of the iris 30. This is advantageous when stents that mustbe cooled or chilled in order to reduce their diameters. For example,Nitinol stents must be cooled in order to reduce the diameter of thestent from an expanded diameter to a delivery diameter. The chiller maybe integrally formed with the crimping system or may be a separatecomponent that may be designed to work in conjunction with theapparatus.

Further still, it is contemplated that the end plates, drive plates orblades may be modified in order to function correctly with the chillerunit. The crimp aperture 21 itself, formed by the blades, is a highlyinsulated chamber, and is suitable for cryogenic processing. Byproviding an end cap 77 or the like, as illustrated in FIG. 10, thedistal end of the crimp aperture 21 can be sufficiently sealed. Asshown, the end cap 77 is formed for insertion into the receiving port 45of the distal stationary end wall 35″. A hub portion of the end cap issized for a friction fit into the receiving port 45, and an O-ring 78forms a fluid tight seal. A set of access ports 80, 81 extend throughthe end cap 77 that provide access to the crimp aperture 21 forselective cooling thereof.

Another embodiment includes cooling of the wedges themselves throughcooling channels or passages. In this configuration, the blades couldinclude communication orifices or the like that communicate a coolantfrom the coolant channels with the crimp aperture for cooling thereof.

Referring now to FIGS. 12-14, another aspect of the present invention isshown in which a stent crimping system, generally designated 100,includes a chassis or base member 101, a crimping assembly 102, aclamping assembly 103 and a control unit 105. The base member 101 isconfigured to retain the crimping assembly 102 and the clamping assembly103 in alignment with one another, wherein the assemblies are alignedalong a longitudinal axis 106. The base member further includesadditional mechanical components (not shown) such as drive motors, loadcells and other control mechanisms that are controlled by the controlunit 105, wherein the control unit is programmed with a machine readablelanguage to operate the mechanical components. In use, the control unit105 may be associated with the control unit of the crimping assembly,wherein the control unit 105 would be utilized to control the expansionand contraction of the iris as described above. The control unit 105 maybe user programmed to control the diameter of the iris within specifiedlimits defined by the user. In the instances where a cryogenic cooler isutilized with the crimping assembly 102 it may be desirable to include afeedback loop within the control unit 105, wherein the feedback loop maybe utilize to calibrate the diameter of the crimping assembly incombination with a quill of known diameter. In accordance with thepresent invention as shown in FIG. 13, there is provided a method ofcalibrating a crimping assembly in accordance with the present inventionwherein the method includes the steps of (1) controlling a crimpingassembly with a control unit, (2) calibrating the control unit with aquill 124 of known diameter by inserting the quill into the iris 110 andreducing the diameter of the iris onto the quill, (3) loading anendoprosthesis within an iris of the crimping assembly, (4) reducing thediameter of the iris to crimp the endoprosthesis, (5) loading theendoprosthesis into or onto a delivery system, and (6) calibrating thecontrol unit. It is desirable to calibrate the control unit of thecrimping assembly if a cryogenic cooler is being utilized during thecrimping process due to tolerance changes of the iris as a result ofcontraction or expansion of the crimping assembly. By calibrating thediameter of the iris prior to crimping of the endoprosthesis a moreconsistent crimp diameter is achieved which is an improvement overconventional crimping techniques. It shall be understood that theprocess described above should be considered exemplary and not limitingin any manner. It is contemplated that the process may be modified, suchas reducing or increasing the number of calibration cycles, utilizing acooler before/during/or after the crimping process or other similarchanges without departing from the scope of the invention.

The crimping assembly 102, as shown in FIG. 13, includes a plurality ofwedges or blades 107 arranged in a wedge assembly 108 that forms an iris110. At the center of the iris 110 is a crimp aperture 111 that iscollectively formed by the distal end 112 of the blades 107. Thecrimping assembly 102 further includes a housing 113 having opposed endplates 115′ and 115″, opposed drive plates 116′ and 116″, a rotation arm117, and rotator links 118′ and 118″. Disposed within the housing 113 isthe wedge assembly containing the plurality of blades 107. Each blade107 is associated with the opposed end plates 115′, 115″ and the driveplates 116′, 116″ of the housing.

These blades 107 of the wedge assembly 108 are configured to translate,whereby the diameter of the cylindrical crimp aperture 111 changesrelative to the translation of the plurality of blades 107. Thetranslation of the blades 107 may be performed manually by a user of theapparatus or, in a preferred embodiment, the crimping assembly 102 maybe controlled by a control unit 105. The control unit, for instance, isprovided by a computer or the like, wherein the computer includes aprogram designed to control the translation of the plurality of blades.

FIG. 14 best illustrates that blade 107 includes a proximal end 120 andthe distal end 112, wherein a first side 121 and an opposed second side122 adjacent to the distal end converge to form a tip 123. This tip 123may be a sharp edge or may be slightly rounded or beveled as mentionedabove. Each blade 107 may be constructed of a material or a combinationof materials such as nylon, delrin, steel, aluminum, titanium, TEFLON @,plastics, composite materials, and other suitable materials. It isfurther contemplated that the blade 107 may be constructed of multiplepieces that may be assembled to form a unitary member, or alternativelyblade 107 may be constructed as a unitary member.

It is further contemplated that blade 107 may further include a coatingdisposed thereon. For example, blade 107 may be coated with a coatingthat is configured to reduce friction, increase hardness, or alter othermechanical properties of the device according to the present invention.To reduce friction between adjacent blades or to reduce friction betweenthe distal end portion of the blade and stent to be crimped, it iscontemplated that the blade may be polished to a high degree in additionto or instead of coating the blade. For example, if it is desirable toform a blade of stainless steel, the blade may be constructed having ahighly polished surface finish to reduce friction and to further reducethe possibility of scratching or otherwise damaging a stent to becrimped.

The blade 107 further includes a pair of opposed pivot pins 125′, 125″disposed on each end section of the blade, wherein the pivot pins arealigned along an axis extending through a centerline plane of the bladeand tip 123. In addition to the pivot pins 125′, 125″, the blade 107further includes a pair of opposed sliding mechanisms 126′, 126″disposed proximal to the respective pins 125′, 125″ and adjacent theproximal end 120 of the blade.

These sliding mechanisms 126′, 126″ comprises first members 127′, 127″and second members 128′, 128″, wherein the respective first members127′, 127″ are fixedly attached to the opposed ends of the blade 107 andthe respective second members 128′, 128″ are slideably received by thecorresponding first member 127′, 127″. As will be described in greaterdetail below with reference to additional drawing figures, therespective second members 128′, 128″ are configured to be fixedlyattached to a corresponding end plate 115′, 115″ of the crimpingassembly 100.

Referring now to FIGS. 15 and 16 there is shown the end plates 115′,115″ in accordance with the present invention, only end plate 115′ ofwhich will be described in detail. As shown, end plate 115′ includes anaperture 130′ extending therethrough from an outer surface to an innersurface. A recessed portion 131′ surrounds the aperture 130′, which inturn the respective second members 128′ of the sliding mechanism 126′are fixedly supported. Each second member 128′ of the sliding mechanismis fixedly attached to the end plate through suitable means, such as afastener, welding or an appropriate adhesive. As shown, the innersurface 132′ defines the recessed portion 131, sized of a depth similarto that of the depth of second member 128′. Hence, when the blades areslideably mounted to the opposed end plates 115′, 115″, the tolerancebetween the opposed ends of the blades 107 and that of the innersurfaces of the end plates 115′, 115″ is relatively small.

Briefly, FIGS. 13, 17A and 17B illustrate that a respective drive plate116′, 116″ is rotatably disposed into the respective aperture 133′, 133″from the outer side of the respective end plate 115′, 115″. Only onedrive plate 116′ will be described in detail in which the aperture 133′is defined extending therethrough from first side 135′ to a second side136′. The second side 136′ of the drive plate 116′ further includes ahub portion 137′ protruding from the surface thereof. The hub portion137′ is configured to be received within the aperture 130′ of thecorresponding end plate 115′. The hub portion 137′ further includes aplurality of radially extending slots 138′ that are disposed about thecircumference of the hub. The slots 138′ are configured to slideablyreceive the pivot pin 125′ of the blades 107.

The end plates and the drive plates, as well as nearly all thecomponents of the embodiments disclosed, may be constructed of materialssuch as metal, plastics or composites. In a preferred embodiment the endplates and the drive plates are constructed of rigid materials such asmetal, such as steel or aluminum. The drive plates may be coated with amaterial to reduce friction between the drive plate and the end platewhere the drive plate rotates within the aperture formed in the endplate.

Referring back to FIG. 13, there is shown an exemplary embodiment of thecrimping assembly 102 in a partially exploded top perspective view. Asillustrated, the crimping assembly 102 includes a housing 113 having twoend plates 115′, 115″ coupled together by a two or more cross-beam 140.It will be appreciated, of course, that the blades 107 of the crimpingassembly 102 could be enclosed entirely by enclosure structure as well,similar to the embodiment of FIGS. 1-11 above.

The crimping assembly further includes the two drive plates 116′, 116″and an actuation device 141 comprising the laterally extending rotationarm 117 flanked by a pair of opposed rotator link 118′, 118″ fixedlymounted to the corresponding drive plates 116′, 116″. Disposed withinthe housing 113 is the wedge assembly 108 comprising the plurality ofblades 107 such as those described in detail above. As assembled, eachblade 107 is associated with each end plate 115′, 115″ at opposed sidesthereof through the sliding mechanism 126′, 126″ and with each driveplate through the pivot pin 125′, 125″, for movement of the iris 110from the first diameter to the reduced second diameter.

In accordance with the present invention, the crimping system shown anddescribed herein may be utilized to reduce the diameter of a medicaldevice (not shown) such as a stent from a first diameter to a seconddiameter. The stent may be comprised of either balloon expandable stentsor self-expanding stents. The plurality of blades of the crimpingassembly 102 are configured to be movable, wherein the distal portionsof the blades and the blade tips form an iris 110 having the crimpaperture 111. The aperture may be moved between a first diameter and asecond diameter, wherein the first diameter is of sufficient size toreceive an expanded or uncrimped stent. After placing the sent withinthe crimp aperture 111 of the iris 110, a force is applied to either therotation arm 117 or rotator links 118′, 118″, thereby rotating the driveplate 116′, 116″. During rotation of the drive plates 116′, 116″ aboutthe rotational axis 142, the interior walls defining the radial slots138′, 138″ of the second side 136′, 136″, cause the blade tips 123 topivot about the pivot pins 125′, 125″, while linearly translating in thedirection of the respective slider mechanism 126′, 126″. Thiscombination of motion causes closure of the blade tips 123 (and hencethe crimp aperture 111 of the iris 110) from the first diameter to thesecond diameter. Accordingly, the rotation of the drive plates aretranslated to the plurality of blades which are in communication withthe drive plates, via the opposed slider mechanism 126′, 126″ and pivotpins 125′, 125″.

The rotation arm or rotator links can be rotated manually by a user orautomatically through the control system of the present invention. Ifthe stent is a balloon expandable stent, prior to applying a force tothe blades, a delivery system such as a balloon catheter is disposedwithin the crimp aperture, whereby as the aperture is drawn closed thestent is crimped about the balloon of the delivery device.

In another aspect of the present invention, the clamping assembly 103 isshown and described in detail in reference to FIGS. 18-21. This clampingassembly 103 is particularly suitable for securing a medical device,such as a delivery catheter for pre-operative preparation applications.For example, as shown in the schematic diagram of FIG. 12, a deliverycatheter (not shown) may be secured by the clamp assembly 103 while it'sdelivery portion is aligned along the longitudinal axis 106 and disposedin the crimper assembly 102 so that a crimp procedure can be performed.

Briefly, the clamping assembly 103 includes a lower clamp device 145, anupper clamp device 146, two opposed pivot levers 147′, 147″, a catheterretaining assembly 148, and a clamp actuation mechanism 150. As will bedetailed below, these components cooperate to move the retainingassembly 148 between an opened condition (FIGS. 19, 21, 24 and 26),enabling insertion and positioning of the delivery device therein, and aclosed condition (FIGS. 20, 22, 25 and 27), clamping the delivery devicein place.

The lower clamp device 145 includes an elongated base 153 with a supportplate 151 extending distally therefrom. The base 153 and the supportplate 151 define a half-round or semi-circular-shaped seating groove 152extending along an upper edge thereof (FIGS. 18, 20 and 26). This groove152 is configured to receive a specific sized delivery device. In theevent that other delivery devices are to be utilized with the clampassembly 103, the groove 152 should be sized accordingly. It will beappreciated that the groove 152 need not be perfectly semi-circular. Forexample, it may be semi-polygonal shaped as well. The diameter or widthof the groove 152, however, should be at least the same as the outerdiameter of the delivery device.

The elongated support plate 151 includes an elongated slot 156 that isoriented vertically. As will be described below, this elongated slotaccommodates a securing pin 171 that mounts the pivot levers 147′, 147″to the retaining assembly 148, during movement of between the openedcondition and the closed condition. The lower clamp further includes apair of opposed pivot pins 157 extending outwardly in a directionsubstantially perpendicular to the elongated support plate.

The upper clamp device 146 is utilized to mount the clamp assembly 103to the base 101, and in alignment with the crimping assembly 102 (FIG.12). It shall be understood, however, that the upper clamp device 146may not be required in order for the clamp assembly to function asdesired. As best shown in FIGS. 20 and 23, the upper clamp device 146also includes an elongated base having a rectangular shaped channel 158extending along a lower edge portion thereof. The upper clamp devicechannel 158 is significantly wider than the seating groove 152 of thelower clamp device 145. When the upper clamp device 146 is mounted tothe lower clamp device 145, a collective receiving channel is formed(FIGS. 24 and 25) that can accommodate the entire transversecross-sectional dimension of the delivery device therethrough.

The catheter retaining assembly 148 includes an elongated U-shapedelastomeric member 160, a pair of spaced-apart inner plates 161′, 161″and a pair of spaced-apart outer plates 162′, 162″. The U-shapedelastomeric member is inverted such that an elongated contacting groove163 thereof faces downwardly, in opposed relation to the elongatedseating groove 152 of the lower clamp device support plate 151. Eachdownwardly depending side wall of the elastomeric member 160 isstraddled by a respective inner plate 161′, 161″ and a respective outerplate 162′, 162″. These plates are secured together with the appropriatefasteners (e.g., screws, bolts, rivets or similar attachment devices andmethods), and provide structural support to the elastomeric member 160.

When the retaining assembly 148 is moved to the closed condition (FIGS.20, 22, 25 and 27), the elongated contacting groove 163 thereof contactsan upper side of the delivery device, and urges it securely againstseating groove 152 of the support plate 151. Hence, the elastomericmember 160 is preferably composed of an elastic material that providessufficient elasticity to secure the delivery device without threateningthe integrity of the delivery device components or materials. By way ofexample, the elastomeric member 160 may be composed of silicon rubber,rubber, latex, PVC or similar materials.

The two inner plates 152 include a downwardly depending vertical wingportion 165′, 165″, each of which is employed to cooperate with thepivot levers 147′, 147″ for movement thereof between the opened andclosed conditions. As best illustrated in FIGS. 19, 20, 24 and 25, thepivot levers 147′, 147″ include pivot apertures 166′, 166″ formed toreceive the pivot pins 157 of the lower clamp device. A proximal end ofthe pivot levers 147′, 147″ includes a contact block 167 disposedbetween the two levers for structural integrity thereof. At a distal endof each pivot lever 147′, 147″ is a pin receiving slot 168′, 168″, eachof which is configured for co axial alignment with a pin receiving port170′, 170″ in the inner plate wing portions 165′, 165″. When the pinreceiving slot 168′, 168″ and 170′, 170″ are co-axially aligned with thevertical slot 156 of the elongated support plate 151, a securing pin 171is passed therethrough to mount these components together. Accordingly,as the pivot levers 147′, 147″ are caused to rotate about a rotationalaxis 174 (FIGS. 26 and 27) of the pivot pins 157, the retainingassembly, via the distal end of the pivot levers 147′, 147″ and thesecuring pin 171, is caused to move between the opened condition (FIGS.19, 21, 24 and 26) and the closed condition (FIGS. 20, 22, 25 and 27).

The lever pin receive slot 168′, 168″ are horizontally or laterallyelongated while the support plate elongated slot 156 is verticallyelongated. In either case, these slots are configured to accommodate thetravel of the securing pin 171 during reciprocal movement of theretaining assembly between the opened condition and the closedcondition.

Briefly, the movement of the pivot levers 147′, 147″ is controlledthrough the clamp actuation mechanism 150 that is configured to contactthe contact block 167 at the proximal end thereof. As best illustratedin FIGS. 23-25, the actuation mechanism 150 includes a clamp bracket 172and a support base 173 that is configured to mount the clamp bracket tothe lower clamp device 145. The clamp bracket 172 includes a bracketbase 175, a lever member 176, a contact lever 177 and a four-bar linkageassembly 178 that cooperates to move the contact lever 177 between afirst position (FIG. 24) and a second position (FIG. 25). In the secondposition, contact lever 177 contacts the contact block 167, and rotatesthe pivot levers about the pivot pin rotational axis 174.

The contact lever 177 can include a threaded contact screw 180 or thelike that can be adjusted to adjust the contact against the contactblock. While this one clamp actuation mechanism embodiment is shown anddescribed, it will be appreciated that other conventional mechanism canbe employed as well.

In operation, when the clamping assembly 103 is in the opened condition(FIGS. 19, 21, 24 and 26), the lever member 176 of the clamp actuationmechanism 150 is manually operated to move the contact lever 177 fromthe first position (FIG. 24) to the second position (FIG. 25), via thelinkage assembly 178. In the second condition, the contact lever 177moves the contact screw 180 against the contact block 167 with a forcesufficient to urge the proximal end of the pivot levers 147′, 147″ aboutthe pivot pins 157. As the pivot lever 147′, 147″ rotates about therotational axis 174 of the pivot pins 157, the distal end of the leversurge the catheter retaining assembly 148, via the securing pin 171,toward the closed position (FIGS. 20, 22, 25 and 27). Accordingly, thedownward force of the elastomeric member 160 of the catheter retainingassembly thereby retains the catheter or delivery device between theretaining assembly and the seating groove 152 at the support plate 151.

In addition to that described above, an important functionality of thisclamp assembly is its ability to hold and retain a stent delivery devicewith sufficient force to prevent the device from moving relative to theclamp but with not too large a force where the delivery device isdamaged. The force applied to the delivery device may be adjusted byadjusting the properties of the elastomeric material or by adjusting theclamping force applied to the elastomeric material by the clampingassembly.

As set forth above with crimping assembly of FIGS. 1-11, it is furthercontemplated that the crimping system 100 in accordance with the presentinvention may additionally include a chiller unit (not shown) whereinthe chiller unit is configured to chill or cool the crimping assembly102 such that the crimping assembly 102 may then be utilized with stentsthat must be cooled or chilled in order to reduce their diameters. Forexample, Nitinol stents must be cooled in order to reduce the diameterof the stent from an expanded diameter to a delivery diameter. Thechiller may be integrally formed with the crimping system 100 or may bea separate component that may be designed to work in conjunction withthe apparatus. Further still, it is contemplated that the end plates,drive plates or blades may be modified in order to function correctlywith the chiller unit.

If the stent to be crimped is a self-expanding stent, prior to applyinga force to the blades, a delivery device is disposed within the clampassembly. Once the stent has been crimped to a desirable deliverydiameter, the clamp assembly is advanced toward the crimping assembly,or alternatively, the crimping assembly is advanced toward the clampassembly, wherein the crimped stent is then disposed within the deliverydevice and the opening is enlarged by either removing the applied forceor applying a force opposite of that previously applied.

Although the present invention has been described in connection with thepreferred form of practicing it and modifications thereto, those ofordinary skill in the art will understand that many other modificationscan be made thereto within the scope of the claims that follow.Accordingly, it is not intended that the scope of the invention in anyway be limited by the above description, but instead be determinedentirely by reference to the claims that follow.

What is claimed:
 1. A method of calibrating a crimping assembly,comprising: controlling a crimping assembly with a control unit;calibrating the control unit by inserting a quill of a known diameterinto an iris of the crimping assembly and reducing a diameter of theiris onto the quill; loading an endoprosthesis within the iris of thecrimping assembly; and reducing the diameter of the iris to crimp theendoprosthesis.
 2. The method of claim 1, wherein the control unit isoperably coupled to a drive mechanism and programmed to operate thedrive mechanism to control an expansion and a contraction of the iris.3. The method of claim 1, wherein the crimping assembly comprises: apair of spaced end plates; a pair of spaced drive plates, each rotatablyassociated with one of the end plates about a rotational axis thereof; aplurality of blades disposed between the drive plates and disposed aboutthe rotational axis; each blade having a first end section and anopposed second end section, each end section being pivotally coupled tothe respective drive plates; each blade having a proximal edge and adistal edge, and a tapered portion adjacent to the distal edge, thedistal edge being parallel to the rotational axis, wherein a first sideand a second side of the tapered portion of each blade is arrangedsubstantially adjacent a second side and a first side, respectively, ofthe tapered portion of an adjacent blade such that the distal edgeportions collectively form an iris, said iris defining a crimp aperture.4. The method of claim 1, further comprising: cooling the crimpingassembly with a cryogenic cooler; and calibrating the control unitduring the crimping process to adjust for a tolerance change of the irisas a result of a contraction or an expansion of the iris.
 5. The methodof claim 1, wherein the control unit is programmed with machine readablelanguage for sending instructions to a drive motor.
 6. The method ofclaim 1, wherein the control unit is programmable to control thediameter of the iris within specified limits.
 7. The method of claim 1,wherein the control unit includes a feedback control loop forcalibrating the diameter of the iris using the quill of a knowndiameter.
 8. A method of calibrating a crimping assembly, comprising:controlling a crimping assembly with a control unit; calibrating thecontrol unit by inserting a quill of a known diameter into an iris ofthe crimping assembly and reducing a diameter of the iris onto thequill; loading an endoprosthesis within the iris of the crimpingassembly; reducing the diameter of the iris to crimp the endoprosthesis;loading the endoprosthesis into or onto a delivery system; andcalibrating the control unit.
 9. The method of claim 8, wherein thecontrol unit is operably coupled to a drive mechanism and programmed tooperate the drive mechanism to control an expansion and a contraction ofthe iris.
 10. The method of claim 8, wherein the crimping assemblycomprises: a pair of spaced end plates; a pair of spaced drive plates,each rotatably associated with one of the end plates about a rotationalaxis thereof; a plurality of blades disposed between the drive platesand disposed about the rotational axis; each blade having a first endsection and an opposed second end section, each end section beingpivotally coupled to the respective drive plates; each blade having aproximal edge and a distal edge, and a tapered portion adjacent to thedistal edge, the distal edge being parallel to the rotational axis,wherein a first side and a second side of the tapered portion of eachblade is arranged substantially adjacent a second side and a first side,respectively, of the tapered portion of an adjacent blade such that thedistal edge portions collectively form an iris, said iris defining acrimp aperture; the control unit sending instructions to a drive motorfor rotating the drive plates about the rotational axis causing thedistal edge of the plurality of blades to pivot while linearlytranslating along respective slider assemblies for movement of the irisfrom a first diameter to a second diameter.
 11. The method of claim 8,further comprising: cooling the crimping assembly with a cryogeniccooler; and calibrating the control unit during the crimping process toadjust for a tolerance change of the iris as a result of a contractionor expansion of the crimping assembly.